Present patent application is filed in the U.S. Provisional Patent Application series No.60/838988 on August 1st, 2006, the priority that is filed in the U.S. Provisional Patent Application series No.60/821032 on August 1st, 2006 and is filed in the serial No.60/820888 of U.S. Provisional Patent Application on July 31st, 2006 based on also requiring, and its content is incorporated into way of reference at this full text.
Also with reference to the U.S. Patent application that is filed in common transfer on the same day therewith, name is called " LED Mosaic " (LED mosaics) (attorney 62370US006); Be filed in U.S. Patent application on the same day therewith, name is called " Combination Camera/ProjectorSystem " (camera/projector's combined system) (attorney 62369US006); Be filed in U.S. Patent application on the same day therewith, name is called " LED Source With HollowCollection Lens " (the LED source with hollow convergent lens) (attorney 62371US006); Be filed in the U.S. Patent Application Serial Number No.11/322 on December 30th, 2005,801, " LED With Compound Encapsulant Lens " (LED) with compound encapsulated-lens; Be filed in U.S. Patent application on the same day therewith, name is called " OpticalProjection Subsystem " (optical projection subsystem) (attorney 6328 1US002); Be filed in the U.S. Patent application sequence No.11/772609 on July 2nd, 2007, name is called " LED Illumination System With PolarizationRecycling " (having the recycling LED illuminator of polarization); And U.S. Patent application US2006/0091411 (people such as Ouderkirk) " High Brightness LED Package " (high-brightness LED encapsulation); US2006/0091798 people such as () Ouderkirk " HighBrightness LED Package With Compound Optical Element (s) " (high-brightness LED encapsulation) and US2006/0092532 people such as () Ouderkirk " High Brightness LED Package With Multiple Optical Elements " (high-brightness LED encapsulation) with a plurality of optical elements with composite optic element.
Background technology
Light source module is widely used in illuminator most, and it has multiple application, comprises the projection display, the be used for LCD backlight or the like of (LCDs).Optical projection system generally includes light source, illumination optics, imaging device, projection optical device and projection screen.Illumination optics is collected the light that comes from light source and in a predefined manner it is directed to one or more imaging devices.The imaging device generation that the digital video signal of being reconciled and being handled by electronics is controlled is corresponding to the image of vision signal.Projection optical device's enlarged image and it is projected on the projection screen subsequently.In conjunction with the white light source (for example arc lamp) of colour filter and will be mainly as the light source of projection display system.Yet recently because the long life-span of light-emitting diode (LED), higher efficient and superior thermal characteristics, it is introduced into alternatively.
LED generally includes LED crystal grain or the chip that is assemblied on the metal joint.This joint can be furnished with reflector, assembling LED crystal grain in the cup, and electrical lead is connected to LED crystal grain.Some encapsulation also can comprise molded transparent resin, form capsule and seal LED crystal grain.The capsule encapsulating resin can have the hemispherical front surface of the nominal of the light keeping parallelism that makes the crystal grain ejaculation in the part, perhaps has the flat surfaces of nominal.In addition, in order to reduce the amount of the light that is trapped in crystal grain inside, can with the optical element contact or near the surface of LED crystal grain with therefrom coupling or " extraction " light.
In addition, can form on the LED luminous element or arrange that extracting structure comes out from LED crystal grain to help coupling light, thereby it is wherein stranded and be wasted to suppress light.For example, make the light-emitting area roughening of LED crystal grain or on this surface, suppress a large amount of facet or other structures (for example sub-wavelength structure) can be used for improving light extraction from LED crystal grain.Other extract structure and comprise high photon crystal structure and the wiregrating extraction parts of extracting. also other extraction structure comprises glass or ceramic extractor or extractor arrays, as at U.S. Patent Application Publication US2006/0091411 (people such as Ouderkirk) " High Brightness LED Package (high brightness LED package) ", disclosed among US2006/0091798 (people such as Ouderkirk) " High BrightnessLED Package With Compound Optical Element (s) (high brightness LED package with composite optic element) " and the US2006/0092532 (people such as Ouderkirk) " HighBrightness LED Package With Multiple Optical Elements (high brightness LED package with a plurality of optics elements) ".
Latest developments in solid-state lighting elements, optical element and display device make and can generate minimum, full color projector.In order to make these color projectors enough little of to be compounded in the mobile phone, the device of probing into very effective and compact combination colour is necessary.There are two kinds of methods in the highest flight that produce colour projection.First method, " look preface " by name, use dichroic X pipe comes from the light of each red light source, green light source and blue-light source with stack and these colors is imaged on the monochromatic micro-display with specific time sequential mode.Second method, " colour filter " by name requires white light source is imaged on the micro-display with the red/green filter.
Above-mentioned discussion only provides general background information, is not that intention is as the scope that helps to determine to be subjected to the theme of claims protection.
Embodiment
Except other, disclosed embodiment of this invention provides and has been used for effective mechanism that light is extracted from led light source.If desired, disclosed embodiment of this invention can also be used to make up the color that comes from the LED luminous element.These disclosed embodiment of this invention allow the look preface and the colour filter technology of compacter version by eliminating in look preface method the needs of X pipe and eliminating needs (they have been used for the look preface and the colour filter method of colour projection traditionally) to anamorphote and Fresnel lens.
In addition, use integrator rod/tunnel techniques more disclosed herein, can use on the surface of crystal grain, to have the LED that extracts structure and the light extraction function that does not influence the expection of these structures.Be not shown specifically in accompanying drawing of the present disclosure although extract structure, each embodiment disclosed herein should be interpreted as containing these structures alternatively, although do not require these structures.
Design disclosed in this invention is opposite with existing instruction content to a certain extent; the unique method of extraction efficiency that improves high index of refraction LED crystal grain or chip in the existing instruction content is for sealing it in the medium with the highest available refractive index (that is, as much as possible near refractive index of LED crystal grain).Adopt basic example of the led light source of this existing instruction to be called in the U.S. Patent application name shown in the prior art Figure 1A of " Light Emitting Diodes with Improved Light ExtractionEfficiency (having the light-emitting diode that improves light extraction efficiency) " (US 2002/0030194A1).This light source comprises with crystal grain or chip form and is arranged in LED luminous element on the metal joint.The lead-in wire bonding is provided to the electrical connection of LED luminous element.Luminous element be bonded to for the light by active region emission have be preferably more than about 1.5, more preferably on the transparent optical element greater than about 1.8 refractive index.
As mentioned above, disclosed embodiment of this invention departs from traditional wrapper technology, and opposite medium or the optics that utilizes the relative low-refraction between LED luminous element and follow-up optics.This beneficial effect is similar to above-mentioned and is called " LEDSource with Hollow Collection Lens (the LED source with hollow convergent lens) " with reference to the U.S. Patent application name, and at U.S. Patent application series No.11/322,801 be called in " LED With CompoundEncapsulant Lens (LED) " with compound encapsulated-lens disclosed those, different is the other beneficial effect that can also utilize integrated optical device in the disclosure.
In an embodiment shown in Figure 1, integrated optical device has spherical cavity, the beneficial effect that this spherical cavity provides is to have provided the space for lead-in wire bonding or other at the lip-deep bulge-structure of LED, and collecting the light that comes from LED effectively, this LED has for the good extraction structure of air interface work.Make this air gap follow spherical surface rather than flat surfaces is normally preferred to minimize Fresnel loss (especially for the light with very high angle outgoing LED).In this case, for taking place with the minimum Fresnel loss of the light of vertical angle incident.Suppose that LED is a lambertian emitter, more outgoing crystal grain to airborne light will be caught by spherical surface, because the trend of more rays is with subvertical angle.
Now referring to accompanying drawing of the present disclosure, similar element like the reference numbers designate wherein, the exemplary embodiment of the schematically illustrated illuminator of the present disclosure of Fig. 1, it can be used for projection application.Comprise luminous element 15 with light-emitting area 17 at the light source module shown in Fig. 1 10.Light-emitting area 17 can be light-emitting area layer of fluorescent powder or any other luminescent material that maybe can comprise LED.Luminous element 15 is arranged in assembly surface or the substrate 25, and can have alternatively be arranged in luminous element 15 and the surface 25 between or other local radiators 20.Being arranged between luminous element 15 and the surface 25 although illustrate, is not to need radiator 20 in all embodiments, neither be positioned at this concrete position for radiator.
Light source module 10 also comprises integrated optical device 30, its to small part hollow be assemblied in light-emitting area 17 tops of luminous element 15.In this specific embodiment, integrated optical device is the post integrator of taper.Most of example as herein described is with reference to tapered rod integrator 30 and 130 (describing in conjunction with Fig. 7 at first).Yet these only are the example to the integrated optical device of small part hollow, and disclose other examples of this optics.For example, the tunnel integrator of introducing in Figure 12 230 is another this integrated optical devices.Although described multiple structure, be to be understood that these structures also can exist for the integrated optical device of the hollow at least in part of the disclosed type of any the present invention in conjunction with the integrated optical device of one type integrated optical device or another kind of type.
Again with reference to figure 1, can integrator 30 be assemblied on the light-emitting area 17, comprise by integrator 30 being assemblied in other surfaces and go up (for example, the surface of surface 25 or radiator 20) by any desired technology or structure.Tapered rod integrator 30 has near-end 35 and far-end 45.Near-end 35 is towards light-emitting area 17, and far-end 45 backward luminous surfaces.The near-end 35 of integrator 30 is provided at the surface 31 that luminous element 15 tops form spherical cavity 40.The far-end 45 of integrator 30 provides the surface 46 that optics and/or film can be disposed thereon.Between top surface 46 and lower surface 31, integrator 30 has tapered sidewalls 32 and 33.
In the exemplary embodiment, the cavity 40 that is provided by tapered rod integrator is filled with the material with refractive index n 1, and refractive index n 1 is less than the refractive index n 2 of tapered rod integrator.In various embodiments, the material in cavity 40 can be air (comprising any of multiple gases or admixture of gas) or liquid.Liquid can be encapsulant gel.In certain embodiments, refractive index n 1 will be near 1.0, but can be up to 1.5 in other exemplary embodiments that also have.Other values of n1 also are fine.No matter the value of n1 how, in general, n1 will be less than n2.In the exemplary embodiment, the refractive index n 2 of tapered rod integrator will be at least 2.0, and in general will be about 2.4 or higher.
Referring now to Fig. 2 A,, the schematic plan according to the light-emitting area 17 of the luminous element 15 of an example embodiment is shown.In this example embodiment, light-emitting area 17 has the array of luminous element 18 (for example luminous element of different color).For example, in Fig. 2 A, the array of luminous element 18 comprises three kinds of different colors (for example red, green and blue), and each is specified by different crosshatches.The color blend that is provided by tapered rod integrator 30 can be provided the multicolour luminous body array of these types.Yet the use of tapered rod integrator 30 is not limited to luminous body array, also can be used for single luminous element as integrator 30.
Luminous element 15 has the width W by luminous element
EHeight H divided by luminous element
EThe aspect ratio that obtains.Provide the end 35 of the tapered rod integrator 30 of spherical cavity 40 also can have aspect ratio.The upward view that Fig. 2 B illustrates integrator 30 makes cavity 40 illustrate.The aspect ratio at integrator 30 35 places in the bottom is the width W of that end of integrator
I-BHeight H divided by that end of integrator
I-BIn some exemplary embodiments, integrator 30 closely mates in the aspect ratio at bottom end 35 places and the size aspect ratio of luminous element.By tight coupling, these aspect ratios can be equal to basically in the exemplary embodiment.
Fig. 2 C illustrates the vertical view of integrator 30, makes cavity top 45 illustrate.The aspect ratio at integrator 30 45 places on the top is integrator width W at that end
I-TDivided by the height H of integrator at that end
I-TIn some exemplary embodiments, the aspect ratio at integrator 30 45 places on the top is rectangular aspect ratio (even the bottom of integrator 30 is not a rectangle).The rectangular aspect ratio on integrator 30 tops 45 does not need closely to mate with the aspect ratio of luminous element and integrator bottom.This has allowed to realize to the conversion of the aspect ratio of expectation.
Referring now to Fig. 3,, another embodiment of light source module 10 is shown, in this light source module, the optics 50 of convergent lens form adheres on the tapered rod integrator.Optics 50 can be for selecting the optical lens components with any kind that reaches special-effect.For example, optics 50 can comprise that collimating lens is to help to produce the collimated light beam that comes from source 10.In addition, replace optical lens, one or more single or multiple lift bloomings 55 can be arranged on the surface 46 of tapered rod integrator 30 to reach the optical results of expectation.This is for example shown in Fig. 4.The example that can be placed on the blooming on the surface 46 comprises and can be used to produce even polarised light and be used to help the recycling reflective polarizer films of light (RPF).The example of reflective polarizer films is multi-layer optical film (MOF) DBEF of Vikuiti brand, by 3M company (3M Company, the St Paul MN.) manufacturing in Sao Paulo, Minnesota State city.Another example that can be placed on the blooming on the surface 46 is quarter-wave plate (QWP), and it can be used to change polarisation of light (for example, from circular polarization to the linear polarization, vice versa).In one embodiment, RPF and QWP both are included in the blooming element 55, and QWP neighbouring surface 46 is to produce polarised light circulation greatly.In other embodiment that also have of light source module 10, for example shown in Figure 5, light source module comprises convergent lens or other optics 50 that adheres on the blooming 55 on the tapered rod integrator 30 by it is arranged in.In another embodiment shown in Fig. 6, mirrored sides 60 is formed by the reflecting material on integrator 30 sidewalls, so that the total internal reflection (TIR) that is provided by integrator 30 and light source module 10 to be provided.
Referring now to Fig. 7-11,, another light source module 100 is shown, it is identical with light source module 10 basically, except some aspect of tapered rod integrator.As shown in Figure 7, light source module 100 comprises the tapered rod integrator 130 of sharing a plurality of structures with above-mentioned tapered rod integrator 30.Similarly, tapered rod integrator 130 has near-end 135 and far-end 145.Near-end 135 is towards light-emitting area 17, and far-end 145 backward luminous surfaces.The far-end 145 of integrator 130 provides the surface 146 that optics and/or blooming can be disposed thereon.Between the top surface 146 and bottom of integrator 130, integrator 130 has tapered sidewalls 132 and 133.Main difference between the integrator 30 and 130 is that the cavity 140 that the light-emitting area top is provided and is arranged in by integrator 130 is truncated pyramidal shaped cavity rather than spherical cavity.Be used to fill identical that the material of truncated pyramidal shaped cavity 140 can be with above-mentioned discussion.Similarly, shown in Fig. 8-11, for example the optics of the multiple combination of convergent lens 50, blooming 55, mirrored sides 60 or these type structures may be used to integrator 130.
Can be shown in Figure 12 with another embodiment that also has that these various features are used.In Figure 12, the light source module 200 of the integrated optical device with tunnel integrator 230 forms is shown.In tunnel integrator 230, cavity 240 stretches upwards to form the tunnel by taper or non-tapered sidewalls 232 and 233.Although not shown in Figure 12, above-mentioned multiple structures in conjunction with tapered rod integrator 30 and 130 descriptions can be used for tunnel integrator 230 in the same manner.What therefore, the sidewall of tunnel integrator 230 for example can be for speculum.As another example,, between tunnel integrator and convergent lens 50, can comprise one or more bloomings for tunnel integrator 230.The content of cavity (for example, the tunnel 240) and regulation also are applicable to tunnel integrator 230 embodiment near the index of refraction relationship that the refractive index of luminous element is lower than the refractive index of follow-up optics.In addition, although the width of the concrete convergent lens size match tunnel integrator 230 that illustrates can also use the convergent lens of other sizes.For example see the broad convergent lens 350 of the tunnel integrator that is used for light source module 300 230 shown in Figure 13.Figure 13 also illustrates the sidewall 360 of speculum, and it can be inwall or outer wall in various embodiments, as above-mentioned described with reference to tapered rod integrator.
Put it briefly, in the exemplary embodiment, light source module comprises the luminous element with at least one light-emitting area, and the integrated optical device to small part hollow that is assemblied in the light-emitting area top.In various embodiments, the refractive index in hollow region is less than the refractive index along the subsequent medium of optical path.
Integrated optical device to small part hollow has towards the near-end of light-emitting area and the far-end on backward luminous surface.In certain embodiments, the near-end of integrated optical device has and the tight matched size aspect ratio of the size aspect ratio of luminous element, and the far-end of integrated optical device is flat, has rectangular aspect ratio.The rectangular aspect ratio of integrated optical device far-end can be different from the size aspect ratio of integrated optical device near-end.
In various embodiments, be included in the tapered rod integrator that the light-emitting area top forms cavity to the integrated optical device of small part hollow, cavity has refractive index n 1 here, less than the refractive index n 2 of tapered rod integrator.Cavity for example can be sphere or truncated pyramidal shaped cavity.Cavity can be filled with air, liquid (for example encapsulant gel) etc., thereby refractive index n 1 is provided.Convergent lens can adhere on the tapered rod integrator, and convergent lens will have the refractive index higher than the refractive index n 2 of tapered rod integrator.One or more bloomings also can be arranged between the far-end of convergent lens and tapered rod integrator.
In other embodiment that also have, comprise the tunnel integrator that is assemblied in the light-emitting area top to the integrated optical device of small part hollow.In these embodiments, light source module will generally include the convergent lens that adheres to tunnel integrator, and convergent lens has refractive index n 2, and it is greater than the refractive index n in the tunnel 1.In the exemplary embodiment that illustrates, tunnel integrator has towards the near-end of light-emitting area and the far-end on backward luminous surface, and the near-end of tunnel integrator forms involucrum above light-emitting area, and the far-end of tunnel integrator is flat, has rectangular aspect ratio.Convergent lens adheres to the far-end of tunnel integrator usually.
Light source module disclosed in this invention can be used for multiple device.In the exemplary embodiment, use the mini projector of look preface of these light source modules can comprise light source module, polarising beam splitter (PBS), monochromatic liquid crystal over silicon (LCOS) panel and projecting lens.Because color can make up and homogenize in tapered tunnel extractor, does not have the needs for color scheme X pipe.In addition, do not have the needs for the anamorphote of regulating aspect ratio, the precursor condition is the aspect ratio of led array and tapered tunnel aspect ratio coupling expectation imaging panel.Adopt the mini projector of colour filter of light source module disclosed in this invention can comprise PBS, colour filter LCOS panel and projecting lens.Alternatively, adopt the mini projector of look preface of these light source modules can comprise light source module, collimating optics device, digital light processing (DLP) panel and projecting lens.
Except as otherwise noted, otherwise all numerals of representation feature size, quantity and the physical property used in specification and the claim all should be understood that it is to be modified by term " about ".Therefore, unless opposite explanation is arranged, the numerical parameter that proposes in above-mentioned specification and the appended claims all is approximations, and it can have difference according to the desirable characteristics that those skilled in the art utilizes instruction content disclosed herein to attempt to obtain.
Concerning those skilled in the art, it is evident that, can under the prerequisite that does not depart from the scope of the present invention with spirit, carry out various modifications and change the present invention.It should be understood that and the invention is not restricted to the exemplary embodiment that this paper provides.